Cutting tool assemblies for such applications as mining or road milling typically comprise a cutting tool, rotatably mounted within a support block. The support block in turn is mounted onto a drum, chain or other body, typically by welding, which in turn is driven by a suitable drive means. A number of such support blocks carrying cutting tools are mounted onto said drum to continually mine and remove material such as coal, rock, asphalt or concrete. The material removed by the cutting tool is pulverized by the cutting tool as each tip is rotated about the drum or chain into contact with the material. Some of the pulverized material collides against the support block and other cutting tool structure. The continual collision of cutting pick and material being removed causes abrasion and wear of the cutting tool and any other components mounted on or near the support block. The wear leads to eventual failure of the tool necessitating downtime of the associated equipment so the worn parts can be replaced.
Wear sleeves have been devised to help protect the front of support block and to provide easily replaceable wear components in comparison to the entire block. It is known to equip a cutting tool assembly with a spray nozzle for spraying fluid onto a cutting tool so as to cool the tool thereby lengthening tool life. It is also known that free rotation of a cutting bit within the support block of the cutting tool promotes tool life by promoting even wear of the cutting bit. Current cutting tool assemblies often affix a shank of the cutting bit within a bore or a wear sleeve of the support block or within the a bore of the support block so the bit can rotate within a bore. It is a common occurrence for the cutting bits to seize within the bore preventing free rotation of the cutting bit and causing premature failure of the cutting bit.
The present invention has been developed in view of the foregoing.